Practical example 1: Spatial performance for audible notification.

The perception of acoustic signaling devices is determined by many factors. In particular, ambient noise and the use of hearing protection must be taken into account. 3D-Coverage shows why.

SOUNDER

AMBIENT NOISE

LENGTH

WIDTH

HEIGHT

3D-COVERAGE

PfannenbergPA 1 100 dB(A)

65 dB

29 m

25 m

29 m

21,025 m³

70 dB

16 m

14 m

16 m

3,584 m³

75 dB

9 m

8 m

9 m

648 m³

80 dB

5 m

4,5 m

5 m

113 m³

85 dB

3 m

2,5 m

3 m

23 m³

Ambient noise can influence safety.

Whether or not the audible signal from a sounder is successfully perceived is not just dependent on the output sound level generated and technology used to create the alarm signal. Ambient noise levels and sounder placement location are crucial elements that should not be overlooked.

The adjacent example illustrates the effect on coverage volume of an 100 dB(A) audible signaling device due to a 10 dB(A) change in ambient noise level. Increasing from 75 dB(A) to 85 dB(A) shows that the warning signal will not be successfully perceived.

The 3D-Coverage values show that the effective covered area is significantly reduced when the ambient noise level rises. If the alarm system designer does not take all aspects into consideration, the consequences can spell danger for people in the surrounding area.